Time to establish an international vaccine candidate pool for potential highly infectious respiratory disease: a community's view

In counteracting highly infectious and disruptive respiratory diseases such as COVID-19, vaccination remains the primary and safest way to prevent disease, reduce the severity of illness, and save lives. Unfortunately, vaccination is often not the first intervention deployed for a new pandemic, as it takes time to develop and test vaccines, and confirmation of safety requires a period of observation after vaccination to detect potential late-onset vaccine-associated adverse events. In the meantime, nonpharmacologic public health interventions such as mask-wearing and social distancing can provide some degree of protection. As climate change, with its environmental impacts on pathogen evolution and international mobility continue to rise, highly infectious respiratory diseases will likely emerge more frequently and their impact is expected to be substantial. How quickly a safe and efficacious vaccine can be deployed against rising infectious respiratory diseases may be the most important challenge that humanity will face in the near future. While some organizations are engaged in addressing the World Health Organization's "blueprint for priority diseases", the lack of worldwide preparedness, and the uncertainty around universal vaccine availability, remain major concerns. We therefore propose the establishment of an international candidate vaccine pool repository for potential respiratory diseases, supported by multiple stakeholders and countries that contribute facilities, technologies, and other medical and financial resources. The types and categories of candidate vaccines can be determined based on information from previous pandemics and epidemics. Each participant country or region can focus on developing one or a few vaccine types or categories, together covering most if not all possible potential infectious diseases. The safety of these vaccines can be tested using animal models. Information for effective candidates that can be potentially applied to humans will then be shared across all participants. When a new pandemic arises, these pre-selected and tested vaccines can be quickly tested in RCTs for human populations.

The role of prenatal violence exposure in the development of disparities in children's adiposity from birth to middle childhood

OBJECTIVE

This study examined whether women's exposure to multiple types of violence during childhood and pregnancy was associated with children's BMI trajectories and whether parenting quality moderated those associations.

METHODS

A cohort of 1288 women who gave birth between 2006 and 2011 self-reported their exposure to childhood traumatic events, intimate partner violence (IPV), and residential address (linked to geocoded index of violent crime) during pregnancy. Children's length/height and weight at birth and at age 1, 2, 3, 4 to 6, and 8 years were converted to BMI z scores. Observed mother-child interactions were behaviorally coded during a dyadic teaching task.

RESULTS

Covariate-adjusted growth mixture models identified three trajectories of children's BMI from birth to 8 years old: Low-Stable (17%), Moderate-Stable (59%), and High-Rising (22%). Children whose mothers experienced more types of IPV during pregnancy were more likely to be in the High-Rising than the Low-Stable (odds ratio [OR] = 2.62; 95% CI: 1.27-5.41) trajectory. Children whose mothers lived in higher crime neighborhoods were more likely to be in the High-Rising than the Low-Stable (OR = 1.11; 95% CI:1.03-1.17) or Moderate-Stable trajectories (OR = 1.08; CI: 1.03-1.13). Main effects of childhood traumatic events and moderation by parenting were not detected.

CONCLUSIONS

Maternal experiences of violence during pregnancy increase children's risk for developing overweight, highlighting intergenerational transmission of social adversity in children's health.

Working memory and school readiness in preschool children with sickle cell disease compared to demographically matched controls

Children diagnosed with sickle cell disease (SCD) are at risk of the development of neurobehavioural problems early in life. Specific impairments in executive function skills, including working memory, have been documented in school-aged children with SCD. These executive skills are known to strongly contribute to early academic skills and preparedness for entering kindergarten. This study examined working memory and school readiness in preschool children with SCD compared to a healthy control group matched for race, sex and parent education. A total of 84 patients diagnosed with SCD (61.9% haemoglobin [Hb]SS/HbSβ0 -thalassaemia) and 168 controls completed testing. The mean (SD) ages of patients and controls at testing were 4.53 (0.38) and 4.44 (0.65) years respectively. The SCD group performed worse than controls on measures of executive function, working memory and school readiness (p < 0.01; Cohen's D range: 0.32-0.39). Measures of working memory were associated with school readiness after accounting for early adaptive development. Multiple linear regression models among patients diagnosed with SCD revealed that college education of the primary caregiver was positively associated with school readiness (p < 0.001) after controlling for sex, genotype, age and early adaptive development. These results highlight the need to implement school readiness interventions in young children diagnosed with SCD emphasising executive function skills.

Bring the life stages into the domain of basic and clinical pharmacology

Completely distinct physiological conditions and immune responses exist among different human life stages. Age is not always consistent with the life stage. We proposed to incorporate the concept of the life stages into basic and clinical pharmacology, including clinical trials, drug labels, and drug usage in clinical practice. Life-stage-based medical treatment is the application of medicine according to life stages such as prepuberty, reproductive, and aging. A large number of diseases are life-stage-dependent. Many medications and therapy have shown various age effects but not been recognized as life-stage-dependent. The same dosage and drug applications used in different life stages lead to divergent outcomes. Incorporating life stages in medicine and drug usage will enhance the efficacy and precision of the medication in disease treatment.

An alternative approach-combination of lockdown and open in fighting COVID-19 pandemics

As the COVID-19 pandemic enters its third year and the omicron variant becomes dominant, we propose an alternative strategy for dealing with COVID-19, called hybrid lockdown, that is, the combination of lockdown (the centralized and organized lockdown of the high-risk population) and free mobility (normal mobility) of the low-risk population. Such an approach will enable a country or region, especially with a high population density, to achieve significant prevention and control the effects of the COVID-19 pandemic at the least cost.

Mortality in Four Waves of COVID-19 Is Differently Associated with Healthcare Capacities Affected by Economic Disparities

Background: The greatest challenges are imposed on the overall capacity of disease management when the cases reach the maximum in each wave of the pandemic. Methods: The cases and deaths for the four waves of COVID-19 in 119 countries and regions (CRs) were collected. We compared the mortality across CRs where populations experience different economic and healthcare disparities. Findings: Among 119 CRs, 117, 112, 111, and 55 have experienced 1, 2, 3, and 4 waves of COVID-19 disease, respectively. The average mortality rates at the disease turning point were 0.036, 0.019. 0.017, and 0.015 for the waves 1, 2, 3, and 4, respectively. Among 49 potential factors, income level, gross national income (GNI) per capita, and school enrollment are positively correlated with the mortality rates in the first wave, but negatively correlated with the rates of the rest of the waves. Their values for the first wave are 0.253, 0.346 and 0.385, respectively. The r value for waves 2, 3, and 4 are −0.310, −0.293, −0.234; −0.263, −0.284, −0.282; and −0.330, −0.394, −0.048, respectively. In high-income CRs, the mortality rates in waves 2 and 3 were 29% and 28% of that in wave 1; while in upper-middle-income CRs, the rates for waves 2 and 3 were 76% and 79% of that in wave 1. The rates in waves 2 and 3 for lower-middle-income countries were 88% and 89% of that in wave 1, and for low-income countries were 135% and 135%. Furthermore, comparison among the largest case numbers through all waves indicated that the mortalities in upper- and lower-middle-income countries is 65% more than that of the high-income countries. Interpretation: Conclusions from the first wave of the COVID-19 pandemic do not apply to the following waves. The clinical outcomes in developing countries become worse along with the expansion of the pandemic.

Variations of COVID-19 mortality are affected by economic disparities across countries

BACKGROUND

When the COVID-19 case number reaches a maximum in a country, its capacity and management of health system face greatest challenge.

METHODS

We performed a cross-sectional study on data of turning points for cases and deaths for the first three waves of COVID-19 in countries with more than 5000 cumulative cases, as reported by Worldometers and WHO Coronavirus (COVID-19) Dashboard. We compared the case fatality rates (CFRs) and time lags (in unit of day) between the turning points of cases and deaths among countries in different development stages and potential influence factors. As of May 10, 2021, 106 out of 222 countries or regions (56%) reported more than 5000 cases. Approximately half of them have experienced all the three waves of COVID-19 disease. The average mortality rate at the disease turning point was 0.038 for the first wave, 0.020 for the second wave, and 0.023 for wave 3. In high-income countries, the mortality rates during the first wave are higher than that of the other income levels. However, the mortality rates during the second and third waves of COVID-19 were much lower than those of the first wave, with a significant reduction from 5.7% to 1.7% approximately 70%. At the same time, high-income countries exhibited a 2-fold increase in time lags during the second and the third waves compared to the first wave, suggesting that the periods between the cases and deaths turning point extended. High rates in the first wave in developed countries are associated to multiple factors including transportation, population density, and aging populations. In upper middle- and lower middle-income countries, the decreasing of mortality rates in the second and third waves were subtle or even reversed, with increased mortality during the following waves. In the upper and lower middle-income countries, the time lags were about 50% of the durations observed from high-income countries.

INTERPRETATION

Economy and medical resources affect the efficiency of COVID-19 mitigation and the clinical outcomes of the patients. The situation is likely to become even worse in the light of these countries' limited ability to combat COVID-19 and prevent severe outcomes or deaths as the new variant transmission becomes dominant.

Intergenerational Transmission of Effects of Women's Stressors During Pregnancy: Child Psychopathology and the Protective Role of Parenting

Objective

Experiences of stress and adversity, such as intimate partner violence, confer risk for psychiatric problems across the life span. The effects of these risks are disproportionately borne by women and their offspring-particularly those from communities of color. The prenatal period is an especially vulnerable period of fetal development, during which time women's experiences of stress can have long-lasting implications for offspring mental health. Importantly, there is a lack of focus on women's capacity for resilience and potential postnatal protective factors that might mitigate these intergenerational risks and inform intervention efforts. The present study examined intergenerational associations between women's prenatal stressors and child executive functioning and externalizing problems, testing maternal parenting quality and child sex as moderators, using a large, prospective, sociodemographically diverse cohort.

Methods

We used data from 1,034 mother-child dyads (64% Black, 30% White) from the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) pregnancy cohort within the ECHO PATHWAYS consortium. Women's prenatal stressors included stressful life events (pSLE) and intimate partner violence (pIPV). Measures of child psychopathology at age 4-6 included executive functioning and externalizing problems. Parenting behaviors were assessed by trained observers, averaged across two sessions of mother-child interactions. Linear regression models were used to estimate associations between women's prenatal stressors and child psychopathology, adjusting for confounders and assessing moderation effects by maternal parenting quality and child sex.

Results

Women's exposures to pSLE and pIPV were independently associated with child executive functioning problems and externalizing problems in fully-adjusted models. Maternal parenting quality moderated associations between pSLE and both outcomes, such that higher parenting quality was protective for the associations between women's pSLE and child executive functioning and externalizing problems. No moderation by child sex was found.

Discussion

Findings from this large, sociodemographically diverse cohort suggest women's exposures to interpersonal violence and major stressful events-common for women during pregnancy-may prenatally program her child's executive functioning and externalizing problems. Women's capacity to provide high quality parenting can buffer this intergenerational risk. Implications for universal and targeted prevention and early intervention efforts to support women's and children's wellbeing are discussed.

Association between population density and infection rate suggests the importance of social distancing and travel restriction in reducing the COVID-19 pandemic

Currently, 2019-nCoV has spread to most countries of the world. Understanding the environmental factors that affect the spread of the disease COVID-19 infection is critical to stop the spread of the disease. The purpose of this study is to investigate whether population density is associated with the infection rate of the COVID-19. We collected data from official webpages of cities in China and in the USA. The data were organized on Excel spreadsheets for statistical analyses. We calculated the morbidity and population density of cities and regions in these two countries. We then examined the relationship between morbidity and other factors. Our analysis indicated that the population density in cities in Hubei province where the COVID-19 was severe was associated with a higher percentage of morbidity, with an r value of 0.62. Similarly, in the USA, the density of 51 states and territories is also associated with morbidity from COVID-19 with an r value of 0.55. In contrast, as a control group, there is no association between the morbidity and population density in 33 other regions of China, where the COVID-19 epidemic is well under control. Interestingly, our study also indicated that these associations were not influenced by the first case of COVID-19. The rate of morbidity and the number of days from the first case in the USA have no association, with an r value of - 0.1288. Population density is positively associated with the percentage of patients with COVID-19 infection in the population. Our data support the importance of such as social distancing and travel restriction in the prevention of COVID-19 spread.

A cost-effective plan for global testing - an infection rate stratified, algorithm guided, multiple-level, continuously pooled testing strategy

The most effective measure to prevent or stop the spread of infectious diseases is the early identification and isolation of infected individuals through comprehensive screening. At present, in the COVID-19 pandemic, such screening is often limited to isolated regions as determined by local governments. Screening of potentially infectious individuals should be conducted through coordinated national or global unified actions. Our current research focuses on using resources to conduct comprehensive national and regional regular testing with a risk rate based, algorithmic guided, multiple-level, pooled testing strategy. Here, combining methodologies with mathematical logistic models, we present an analytic procedure of an overall plan for coordinating state, national, or global testing. The proposed plan includes three parts 1) organization, resource allocation, and distribution; 2) screening based on different risk levels and business types; and 3) algorithm guided, multiple level, continuously screening the entire population in a region. This strategy will overcome the false positive and negative results in the polymerase chain reaction (PCR) test and missing samples during initial tests. Based on our proposed protocol, the population screening of 300,000,000 in the US can be done weekly with between 15,000,000 and 6,000,000 test kits. The strategy can be used for population screening for current COVID-19 and any future severe infectious disease when drugs or vaccines are not available.

THRIVE intervention development: using participatory action research principles to guide a mHealth app-based intervention to improve oncology care

Background:

Women with hormone receptor-positive, early-stage breast cancer who adhere to adjuvant endocrine therapy (AET) reduce the risk of cancer recurrence and mortality. AET, however, is associated with adverse symptoms that often result in poor adherence. We applied participatory action research (PAR) principles to conduct focus groups and interviews to refine and enhance a web-enabled app intervention that facilitates patient-provider communication about AET-related symptoms and other barriers to adherence.

Methods:

We conducted four focus groups with women with early-stage breast cancer on AET (N=28), stratified by race (Black and White) and length of time on AET (<6 months and >6 months), to determine preferences and refine the app-based intervention. A fifth mixed-race focus group was convened (N=6) to refine THRIVE app content using high-fidelity mock-ups and to develop new, tailored feedback messages. We also conducted interviews with oncology nurses (N=5) who participated in the THRIVE randomized controlled trial.

Results:

Participants reported preferences for weekly reminder messages to use the THRIVE app, a free-text option to write in AET-related symptoms, and app aesthetics. Other requested app features included: a body map for identifying pain, sleep and dental problems on the symptom list, a dashboard, tailored feedback messages, and information about social support resources. Participants also developed new intervention messages, decided which messages to keep, and edited language for appropriateness and sensitivity. They also discussed the type of electronic pill monitor and incentive plan to be used in the intervention. Nurses reported THRIVE alerts integrated seamlessly into their clinical workflow and increased patient-provider communication, facilitating quicker response to patients’ reported symptoms. Nurses reported no negative feedback or usability concerns with the app.

Conclusions:

THRIVE app content reflects researchers’ partnership with a racially diverse sample of breast cancer survivors and healthcare providers and adherence to participatory design by incorporating patient-requested app features, app aesthetics, and message content. The app has the potential to improve AET adherence and quality of life among breast cancer survivors and reduce disparities in mortality rates for Black women by facilitating communication with healthcare providers.

Maternal Plasma 25-Hydroxyvitamin D during Gestation Is Positively Associated with Neurocognitive Development in Offspring at Age 4-6 Years

BACKGROUND

Vitamin D is critical to embryonic neuronal differentiation and other developmental processes that may affect future neurocognitive function. However, observational studies have found inconsistent associations between gestational vitamin D and neurocognitive outcomes.

OBJECTIVES

We examined the association of gestational 25-hydroxyvitamin D [25(OH)D] with children's IQ at 4-6 y, and explored whether associations differed by race.

METHODS

This study used data from the CANDLE (Conditions Affecting Neurocognitive Development and Learning in Early Childhood) cohort. Between 2006 and 2011, CANDLE recruited 1503 women in their second trimester of healthy singleton pregnancies. Inclusion criteria for this analysis were gestation of ≥34 wk and availability of 25(OH)D and IQ data. Associations between second-trimester 25(OH)D plasma concentration and Stanford-Binet IQ scores in offspring at 4-6 y were examined using multivariable linear regression; interaction terms were used to explore possible effect modification by race.

RESULTS

Mean ± SD 25(OH)D concentration among 1019 eligible dyads was 21.6 ± 8.4 ng/mL, measured at a mean ± SD gestational age of 23.0 ± 3.0 wk. Vitamin D deficiency [25(OH)D < 20 ng/mL] was observed in 45.6%. Maternal 25(OH)D differed by race with a mean ± SD of 19.8 ± 7.2 ng/mL in Blacks sand 25.9 ± 9.3 ng/mL in Whites ( P  < 0.001). In adjusted models a 10-ng/mL increase in 25(OH)D was associated with a 1.17-point higher Full Scale IQ (95% CI: 0.27, 2.06 points), a 1.17-point higher Verbal IQ (95% CI: 0.19, 2.15 points), and a 1.03-point higher Nonverbal IQ (95% CI: 0.10, 1.95 points). We observed no evidence of effect modification by race.

CONCLUSIONS

Second-trimester maternal 25(OH)D was positively associated with IQ at 4-6 y, suggesting that gestational vitamin D status may be an important predictor of neurocognitive development. These findings may help inform prenatal nutrition recommendations and may be especially relevant for Black and other dark-skinned women at high risk of vitamin D deficiency.

Real-time estimation and prediction of mortality caused by COVID-19 with patient information based algorithm

The global COVID-19 outbreak is worrisome both for its high rate of spread, and the high case fatality rate reported by early studies and now in Italy. We report a new methodology, the Patient Information Based Algorithm (PIBA), for estimating the death rate of a disease in real-time using publicly available data collected during an outbreak. PIBA estimated the death rate based on data of the patients in Wuhan and then in other cities throughout China. The estimated days from hospital admission to death was 13 (standard deviation (SD), 6 days). The death rates based on PIBA were used to predict the daily numbers of deaths since the week of February 25, 2020, in China overall, Hubei province, Wuhan city, and the rest of the country except Hubei province. The death rate of COVID-19 ranges from 0.75% to 3% and may decrease in the future. The results showed that the real death numbers had fallen into the predicted ranges. In addition, using the preliminary data from China, the PIBA method was successfully used to estimate the death rate and predict the death numbers of the Korean population. In conclusion, PIBA can be used to efficiently estimate the death rate of a new infectious disease in real-time and to predict future deaths. The spread of 2019-nCoV and its case fatality rate may vary in regions with different climates and temperatures from Hubei and Wuhan. PIBA model can be built based on known information of early patients in different countries.

Abstract A073: A qualitative exploration of social support needs of diverse patients with breast cancer in the adjuvant phase of treatment

Background: Women diagnosed with breast cancer transitioning from the active phase of treatment to the adjuvant phase of treatment experience fewer opportunities to receive support from their oncology team. During this period of time, the frequently unfulfilled social support needs reported by many oncology patients may be exacerbated for these women. Having social support is a critical component of cancer care and is associated with positive patient outcomes, including medication adherence and survival. Our study uses qualitative methods to evaluate the social support needs of a diverse group of women in the adjuvant phase of treatment and investigate any potential impact on cancer disparities.

Method: Four 90-minute focus groups (N= 28) were conducted among women with breast cancer treatment who were prescribed tamoxifen or aromatase inhibitors, and then stratified by race (Black and White) and length of adjuvant treatment (i.e., &lt; 6 month or &gt; 6 month). These focus groups were held at a regional cancer center in the Mid-Southern US, a region with high Black-White breast cancer outcome disparities. The data were examined in accordance with conventions of thematic analysis to assess many topics related to the breast cancer experience including social support needs.

Results: Both Black and White participants expressed a preference for having frequent and consistent access to providers to minimize feelings of isolation and meet new and persisting emotional and informational social support needs. Specifically, a participant highlighted how critical it was that she was “able to call my primary care provider” and spend “quite some time” so that she could get questions answered and ease her fears. The support from friends and family was also highlighted by the women. In addition, several women from each focus group expressed the importance of having loved ones present during important medical visits. For example, some participants mentioned patients needing “family or anybody around to discuss the findings” or having “someone to hug.” Most notably, participants sought and provided social support to each other in the focus group itself, exhibiting a phenomenon referred to as “experiential social support.” This was best exemplified by several recommendations in each focus group to “form support groups” and “meet once a month” as an outlet to discuss experiences and reciprocally provide support.

Conclusions: Irrespective of race, women in the adjuvant phase of treatment reported needing more resources to meet their social support needs during this period of increased stress and less provider contact. The women found experiential support to be a vital component in meeting social support needs. Providers should consider implementing standardized methods to address the unmet social support needs of patients. For example, providers could assess for deficits in social support on a continuous basis (e.g., screening questions) and offer resources such as support groups and assigned patient advocates to fill gaps.

Citation Format: Andrew J. Paladino, Janeane Anderson, Rebecca Krukowski, Lee Schwartzberg, J. Carolyn Graff, Tameka N. Jones, Gregory A. Vidal, Mehmet Kocack, Ilana Graetz. A qualitative exploration of social support needs of diverse patients with breast cancer in the adjuvant phase of treatment [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A073.

Abstract A005: “Nobody will tell you. You've got to ask!” Race-based differences in patient-provider communication efficacy and social support between Black and White women with breast cancer

Purpose: The purpose of this qualitative research study was to explore patient perceptions of patient-centered communication from oncology care providers among Black and White women taking an adjuvant endocrine therapy (AET) medication to treat breast cancer.

Methods: Four 90-minute focus groups were conducted from December 2017 to January 2018 in Memphis, TN, a Mid-South region of the United States with significant Black-White breast cancer mortality disparities. Focus groups were stratified by race (Black and White) and patient length on AET (i.e., &lt; 6 month AET use or &gt; 6 month AET use) (N=28). They were moderated by a race-concordant moderator, using a semistructured interview guide, and audio recorded, transcribed verbatim, coded according to conventions of value-based coding, and analyzed by emergent themes. Participants were compensated with a notebook and $40 merchant gift card. Results In our study, race-based differences in participants' perceptions of information provision and patient-centered patient-provider communication emerged. Black women were more likely than White women to report being proactive and assertive in requesting information related to AETs. Yet, Black women were less likely than White women to report having their informational needs met by providers, namely treatment length, AET symptom management, and effects of AET on pre-existing chronic conditions. One Black participant said, “Nobody will tell you about it [her lab reports]. You've got to ask! If you don't, you won't get any answers.” White women in our study were more likely to report receiving social support from health care providers and praise longstanding relationships. Conversely, Black women in our study shared personal stories of disempowered, paternalistic interactions with providers and frequently mentioned the importance of changing providers to increase their comfort. As such, they were more likely than White women to report relying on their faith in God and nonmedical social support networks to manage symptoms and adhere to prescribed AET regimens. In addition, unlike White women in our sample, Black women said they had no problem discussing sensitive topics, like sexual dysfunction and menopause, with providers but believed those discussions made their providers feel uncomfortable.

Conclusion: Race-based differences in patient-provider communication may contribute to unmet informational and social support needs among Black women with breast cancer during the AET phase. Findings from our study suggest that Black women, compared to White women, experience poorer patient-provider communication and patient-centered cancer care.

Implications: Study results have implications for cancer care in diverse clinical settings. Communication skills training programs should include cultural competency curricula and help oncologists identify and address social support challenges facing Black female patients during the adjuvant phase of breast cancer treatment.

Citation Format: Janeane N. Anderson, Ryan Blue, J. Carolyn Graff, Rebecca A. Krukowski, Ilana Graetz. “Nobody will tell you. You've got to ask!” Race-based differences in patient-provider communication efficacy and social support between Black and White women with breast cancer [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A005.

The Data set for Patient Information Based Algorithm to Predict Mortality Cause by COVID-19

The data of COVID-19 disease in China and then in South Korea were collected daily from several different official websites. The collected data included 33 death cases in Wuhan city of Hubei province during early outbreak as well as confirmed cases and death toll in some specific regions, which were chosen as representatives from the perspective of the coronavirus outbreak in China. Data were copied and pasted onto Excel spreadsheets to perform data analysis.

A new methodology, Patient Information Based Algorithm (PIBA) [1], has been adapted to process the data and used to estimate the death rate of COVID-19 in real-time. Assumption is that the number of days from inpatients to death fall into a pattern of normal distribution and the scores in normal distribution can be obtained by observing 33 death cases and analysing the data [2]. We selected 5 scores in normal distribution of these durations as lagging days, which will be used in the following estimation of death rate. We calculated each death rate on accumulative confirmed cases with each lagging day from the current data and then weighted every death rate with its corresponding possibility to obtain the total death rate on each day. While the trendline of these death rate curves meet the curve of current ratio between accumulative death cases and confirmed cases at some points in the near future, we considered that these intersections are within the range of real death rates.

Six tables were presented to illustrate the PIBA method using data from China and South Korea. One figure on estimated rate of infection and patients in serious condition and retrospective estimation of initially occurring time of CORID-19 based on PIBA.

Abstract 2428: New school health care: Utilizing technology in the treatment and support of women with breast cancer in the ambulatory setting

Background Adjuvant endocrine therapies (AETs) (e.g. tamoxifen and aromatase inhibitors (AIs) are almost always prescribed to early stage breast cancer (BrCa) patients as AETs have been shown to reduce risk of recurrence and mortality for women with hormone receptor-positive early stage breast cancer. Despite proven efficacy and patient education efforts, AET adherence is suboptimal. Most patients report symptom burden as the most common cause for non-adherence. We conducted focus groups among this patient population to aid in the refinement of a communication app for patients to report symptoms to their healthcare team and receive tailored feedback messages. The app aims to improve AET adherence, symptom management, and quality of life.

Method Four focus groups (N=28), stratified by race (Black and White) and patient length of time on AET ( &lt; 6 months AET use or &gt; 6 months AET use), were conducted in Memphis, Tennessee. The focus groups were audiotaped, transcribed, and analyzed to identify key themes.

Results Participants indicated they would be open to utilizing technology throughout their cancer treatment. The app was viewed as a conduit in the exchange of information between the patient and their healthcare team. Even patients who typically did not use or “like” technology thought the messages and symptom management information would be beneficial. Reporting symptoms through the app and then receiving a phone call from their healthcare team to respond to those symptoms was viewed as the most beneficial component to the patients. One participant stated how she could see the benefit of the symptom reporting feature when first initiating AET therapy: “There were times when I wanted to go tell my doctor, “STOP THIS MEDICINE RIGHT NOW, find me something else to do, find something else besides this because this stuff is not working for me.” In regards to the tailored feedback messaging through the app, participant stated, “I like the one that says, ‘Take meds regularly is an effective way to prevent cancer from coming back,’ because for me that is the only reason why I take it SOME days just to make sure that it doesn’t come back because I HATE the stuff.”

Conclusions Early stage hormone receptor positive breast cancer patients may benefit from utilizing technology in the management of their care. The use of a communication app with tailored feedback messaging has the potential to increase medication adherence, improve symptom management and quality of life, improve the provider- patient relationship, and ultimately reduce mortality. As healthcare shifts toward focusing on patient-centered care and preparing patients to manage their care at home, apps like the one examined in the current study may play a vital role in helping these and other patient populations.

Citation Format: Tameka N. Jones, Andrew J. Paladino, Gregory A. Vidal, Rebecca Krukowski, J. Carolyn Graff, Ryan Blue, Ilana Graetz, Lee Schwartzberg, Mehmet Kocak, Janeane Anderson. New school health care: Utilizing technology in the treatment and support of women with breast cancer in the ambulatory setting [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2428.

Factors Associated With Quality of Life of Family Caregivers of Dialysis Recipients

Chronic kidney failure may contribute to the diminished quality of life of African American women who care for adults affected by the disorder. Few studies document the quality of life of these caregivers. For this descriptive correlational study, caregiver demographic, caregiver burden, depressive symptoms, family functioning, and quality-of-life self-report data from 75 African American women were extracted from an existing database. Ferrans' Conceptual Model of Quality of Life guided the selection of study variables. Several significant associations were found. Caregiver education, employment status, marital status, and caregiver burden explained 63% of the variance in the caregivers' quality of life. Findings support the need to explore further and design interventions to improve the quality of life of working African American women supporting individuals with chronic kidney failure.

Atherosclerotic cardiovascular disease risk assessment and predictors of statin use in Filipino-American Women

WHAT IS KNOWN AND OBJECTIVE

Race and gender disparities in the context of appropriate treatment with lipid-lowering therapies do exist. The 2013 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines outlined four groups, three for primary prevention and one for secondary prevention, whom would benefit from statin therapy to target atherosclerotic cardiovascular disease (ASCVD). The application of these recommendations in Filipino women living in the United States is unknown; however, this population is known to have elevated cardiovascular risk. Socio-economic and clinical characteristics that predict statin utilization of this Asian American subgroup need to be explored.

METHODS

This was an exploratory analysis of data collected during a cross-sectional study of Filipino-American Women (FAW). The Pooled Cohort equation was used to estimate 10-year ASCVD risk. Bivariate analysis was employed to determine the association between statin treatment and clinical and socio-economic factors. Data were analysed using SAS^® 9.4; statistical significance was set at P < 0.05.

RESULTS AND DISCUSSION

A total of 384 women (mean age 56.3 years) were included in the original study, and the average 10-year ASCVD risk was 3.5 ± 3.7%. Upon applying the 2013 ACC/AHA guidelines, 97 FAW were categorized into one of the primary prevention groups. Women considered to benefit from a statin based on the guideline criteria but were not prescribed a statin were considered the not statin treated group (n = 55). From the original cohort, 93 FAW reported current statin therapy use and were categorized as statin treated. The clinical characteristics associated with not being statin treated were as follows: untreated blood pressure (P = 0.012), higher diastolic blood pressure (P = 0.015), higher total cholesterol (P < 0.001), higher triglycerides (P = 0.041), higher low-density lipoprotein (P < 0.001) and higher glucose (P = 0.011). The socio-economic factor associated with not being statin treated was having two or more insurance payers (P = 0.005). Overall, this population had a waist circumference and body mass index (BMI) that exceeds guidelines for Asian women (31.5 or 80 cm).

WHAT IS NEW AND CONCLUSION

Predictors of statin utilization in FAW are not well documented in the literature. These findings emphasize room for improvement for the prescribing of statins in primary prevention for this study population. Applying culturally appropriate screening strategies to identify cardiovascular risk factors early such as BMI or waist circumference may assist with quantifying patients into one of the statin benefit groups if eligible.

A qualitative exploration of race-based differences in social support needs of diverse women with breast cancer on adjuvant therapy

OBJECTIVE

Social support is a critical component of breast cancer care and is associated with clinical and quality of life outcomes. Significant health disparities exist between Black and White women with breast cancer. Our study used qualitative methods to explore the social support needs of Black and White women with hormone receptor-positive breast cancer on adjuvant endocrine therapy (AET).

METHODS

We conducted four focus group (FG) interviews (N = 28), stratified by race (ie, Black and White) and time on AET. FGs were audiotaped, transcribed, and analyzed according to conventions of thematic analysis.

RESULTS

Participants noted the importance of having their informational and emotional social support needs met by friends and family members. White participants reported support provided by others with breast cancer was crucial; Black women did not discuss other survivors as part of their networks. Notably, both White and Black participants used the FG environment to provide experiential social support to each other.

CONCLUSIONS

White participants noted that having other breast cancer survivors in their support network was essential for meeting their social support needs. However, Black participants did not reference other breast cancer survivors as part of their networks. Cancer centers should consider reviewing patients' access to experiential support and facilitate opportunities to connect women in the adjuvant phase.

Quality of Life and African American Women Who are Family Caregivers: A Literature Review with Implications for Psychiatric Mental Health Advanced Practice Registered Nurses

PURPOSE

To identify factors affecting the quality of life (QOL) of African American women (AAW) family caregivers of individuals with kidney failure.

METHODS

Ferrans' Conceptual Model of QOL provided the framework for this literature review. Included studies were (a) peer- reviewed, (b) published within the last ten years, (c) written in English, and (d) examined QOL of AAW family caregivers. Using CINAHL© and PubMed©, we found 14 studies that described factors associated with these caregivers' QOL.

SCOPE

Few studies document the QOL of AAW who are family caregivers, especially in the context of kidney failure. Psychiatric Mental Health Advanced Practice Registered Nurses need to learn about the factors influencing the QOL of these caregivers.

RESULTS

No studies were found within the last ten years that explored the QOL of AAW family caregivers of individuals with kidney failure. Findings reflected the QOL of AAW family caregivers in the context of other chronic conditions. Various factors such as stress, insomnia, and employment were linked to an impaired QOL. Implications for practice, research and education for PMH-APRNs are suggested.

CONCLUSION

PMH-APRNs are uniquely trained to address many factors that affect the QOL of these caregivers and may provide holistic care aimed at promoting satisfactory QOL for these caregivers.

Psychometric evaluation of the nursing child assessment teaching (NCAT) scale in a community-based sample

The effect of the mother-child relationship on long-term child development has received research attention for decades. Because the quality and quantity of mother-infant interactions have been established as important predictors of the child's development, early identification of areas in the relationship requiring support and intervention is essential for promoting positive child outcomes. The Nursing Child Assessment Teaching Scale (NCAT) is an instrument long used to quantify the quality of interaction in the mother-child relationship during the first 36 months of a child's life. While the NCAT has been shown to be a reliable and valid instrument, limited evidence exists of the theoretical congruence between the Barnard Model it is based on and the NCAT scale. The psychometric properties of the NCAT scale and subscales were examined using item response theory in relation to characteristics of interactions in the Barnard Model using data collected during a clinic visit at 12 months of infant age in a sample of mothers and children (N = 1,121 dyads) from a community-based sample in Shelby County, TN. In this secondary analysis, descriptive statistics, reliabilities, and factor loadings for the NCAT were obtained using confirmatory factor analysis and augmented to form multiple indicators, multiple causes models, linking demographic predictors of the mothers and children to the NCAT subscales. Results supported scale abbreviation and theoretical congruence with the Barnard Model, which may provide researchers and practitioners with a more concise, reliable way of measuring maternal-child interaction in community settings.

Male Caregivers of Persons with End Stage Renal Disease: A Qualitative Study

This study explored experiences associated with burden, depressive symptoms, and perceived health in six male caregivers of persons with end stage renal disease (ESRD) using qualitative interviews. Analysis employed open coding and analysis to generate codes and categories. Eighty-three percent of the participants reported significant subjective and objective burden. Linkages occurred between sociodemographic characteristics, care recipient attributes, and caregiver-care recipient relationship, and caregivers' experience of burden and depressive symptoms. Findings suggest the need for intervention trials targeting new coping strategies to help improve the well-being of this population.

Male Caregivers of Persons with End Stage Renal Disease: A Literature Review

This literature review examined burden, depressive symptoms, and perceived health reported by male caregivers of persons with end stage renal disease. These studies suggest that male caregivers often experience negative outcomes. Compared to non-caregivers, male caregivers had higher levels of anxiety and depressive symptoms. Qualitative studies suggest depression is common and associated with conflict between caregiving responsibilities and work, poor caregiver health, and fears about the future outcomes of relatives for whom they provide care. Future research will assist healthcare providers to identify at-risk male caregivers and develop effective interventions to support this understudied caregiver population.

Measuring Health-Related Quality of Life of Adults With Down Syndrome

This study examined self- and caregiver-reported health-related quality of life (HRQOL) of 60 adults with Down syndrome (DS) using the QualityMetric Short Form-12 version 2 (SF-12v2). All HRQOL scores exceeded means and fell within one standard deviation of the SF-12v2 normative sample. Similarities between eight self- and caregiver-reported HRQOL scales were found with the exception of role physical scores (impact of health problems on typical accomplishments), which were lower when obtained by caregiver-report. A positive association was found between self- and caregiver-reported physical functioning scores (impact of health problems on physical activity). The SF-12v2 had high construct validity in this study. These findings support the feasibility of measuring HRQOL of adults with DS using self-report rather than reliance on caregiver-report.

Gestational Vitamin 25(OH)D Status as a Risk Factor for Receptive Language Development: A 24-Month, Longitudinal, Observational Study

Emerging data suggest that vitamin D status during childhood and adolescence can affect neurocognitive development. The purpose of this study was to investigate whether gestational 25(OH)D status is associated with early childhood cognitive and receptive language development. The Conditions Affecting Neurocognitive Development and Learning in Early Childhood Study (CANDLE) study enrolled 1503 mother-child dyads during the second trimester of healthy singleton pregnancies from Shelby County TN. Among 1020 participants of the total CANDLE cohort for whom 25(OH)D levels were available, mean gestational 25(OH)D level during the second trimester was 22.3 ng/mL (range 5.9–68.4), with 41.7% of values <20 ng/dL. Cognitive and language scaled scores increased in a stair-step manner as gestational 25(OH)D levels in the second trimester rose from <20 ng/dL, through 20–29.99 ng/dL, to ≥30 ng/dL. When controlling for socioeconomic status, race, use of tobacco products, gestational age of the child at birth, and age at the 2-year assessment, the gestational 25(OH)D was positively related to receptive language development (p < 0.017), but not cognitive or expressive language.

Transition from pediatric to adult care in sickle cell disease: perspectives on the family role

Transition from pediatric to adult care poses challenges for adolescents with sickle cell disease (SCD). This study explored the transition perspectives of adolescents with SCD, their siblings, and caregivers. Focus groups were conducted with 12 African American families. Adolescents, siblings, and caregivers demonstrated awareness of transition and need for disease management responsibility. Siblings' and caregivers' concerns included adolescent medication adherence. Family concerns included leaving the pediatric environment and adult providers' lack of knowledge. Families recommended more transition preparation opportunities. Family members' perspectives are valuable in informing transition planning. Family-focused interventions designed to prepare and support families during transition are necessary.

Parental stress in families of children with a genetic disorder/disability and the resiliency model of family stress, adjustment, and adaptation

BACKGROUND

Research suggests that parents of children with disabilities endure increased amounts of stress but also experience positive outcomes.

PURPOSE

To further investigate findings from focus group interviews that explored parental stress in families of children with disabilities using a sequential mixed methods design.

METHOD

This study sought to model parental stress using the McCubbin and McCubbin (1993) Resiliency Model of Stress, Adjustment, and Adaptation using qualitative and quantitative data collected sequentially. Twenty-five parents of children with autism spectrum disorder, cerebral palsy, Down syndrome, and sickle cell disease participated in a 2-step study that encompassed qualitative followed by quantitative data ascertainment.

RESULTS

Parents who quantitatively experienced high stress or low stress used different behavioral themes to describe their experience qualitatively. Positive appraisals, resources, and ability to engage in problem solving and coping were associated with family resiliency.

The relationships among adaptive behaviors of children with autism, family support, parenting stress, and coping

BACKGROUND

As the number of children diagnosed with autism continues to rise, resources must be available to support parents of children with autism and their families. Parents need help as they assess their unique situations, reach out for help in their communities, and work to decrease their stress levels by using appropriate coping strategies that will benefit their entire family.

METHODS

A descriptive, correlational, cross-sectional study was conducted with 75 parents/primary caregivers of children with autism. Using the McCubbin and Patterson model of family behavior, adaptive behaviors of children with autism, family support networks, parenting stress, and parent coping were measured.

FINDINGS AND CONCLUSIONS

An association between low adaptive functioning in children with autism and increased parenting stress creates a need for additional family support as parents search for different coping strategies to assist the family with ongoing and new challenges. Professionals should have up-to-date knowledge of the supports available to families and refer families to appropriate resources to avoid overwhelming them with unnecessary and inappropriate referrals.

"It's our job": qualitative study of family responses to ableism

Forty-five parents of children with autism, cerebral palsy, Down syndrome, and sickle cell disease participated in 8 focus groups. Parents discussed how they, the child with the disability, and the siblings addressed community perceptions about the child's disability. Themes evolving from the interviews included (a) support and lack of support, (b) inclusion and exclusion, and (c) the family members' roles during their interactions with the community. Parents viewed their roles in the community as (a) advocating, (b) educating, (c) informing, (d) ignoring, and (e) hiding. The relationship between themes is presented, and the relationship between themes and parent empowerment is discussed as well as the ways in which the themes reflect underlying ableism.

Exploring parent-sibling communication in families of children with sickle cell disease

BACKGROUND

Communication within families of children with sickle cell disease is important yet has not been adequately investigated.

METHODS

Focus group interviews were conducted with parents of children with sickle cell disease to explore parent-sibling communication about sickle cell disease.

RESULTS

Communication was influenced by attributes and behaviors of the parent, the child with sickle cell disease, and the sibling; extended family, neighbors, friends, and church members or social networks; and available, accessible resources related to the child's health, child's school, and parent employment. Outcomes that influenced and were influenced by factors within and outside the parent-sibling dyad and nuclear family included parent satisfaction, parent roles, family intactness, and status attainment.

CONCLUSIONS

These findings support previous research with African-American families and expand our views of the importance of educating parents, family members, and others about sickle cell disease. The findings suggest a need to explore sibling perception of this communication, parent and sibling perception of the impact of frequent hospitalizations and clinic visits on the sibling and family, and variations within families of children with sickle cell disease.

The health-related quality of life of custodial grandparents

Health-related quality of life (HRQOL) was explored in a sample of 119 custodial grandparents. A latent profile analysis identified three groups of grandparents along a continuum of good to poor HRQOL, with most custodial grandparents reporting Short Form-12 Health Survey (version 2) scores significantly below U.S. population means. Grandparent and grandchild characteristics that predicted grandparent HRQOL were identified. Grandchild health problems, number of grandchildren in custody, and grandparent education contributed to a moderate reduction in HRQOL. A large reduction in HRQOL was predicted by depression. Differences in depression were reported between groups, with grandparents with poor HRQOL also reporting clinically significant depression, grandparents with fair HRQOL reporting marginally clinically significant depression, and grandparents with good HRQOL reporting no depression. In a qualitative analysis, grandparent conceptualization of what they need to do to maintain and improve their health was explored for each group. Findings from the quantitative analysis indicate variation in grandparent health and mental health status and suggest that services should be tailored to address grandparent needs. The qualitative analysis highlights the importance of religion and spirituality to grandparents, the economic concerns of grandparents, and the need for transdisciplinary services.

Developmental disabilities: effects on well siblings

BACKGROUND

Forty studies performed between 1970 and 1995 indicated that 60% of parents with children with developmental disabilities reported manifestations of increased risk or negative effects on the well siblings.

METHOD

A secondary data analysis was performed using qualitative data gathered during the baseline of a randomized controlled clinical trial of an intervention for siblings/families of children with long-term conditions, including developmental disabilities. Content analysis was used to identify themes from responses of 151 parents to an open-ended question on their perceptions of the effects on well siblings of living at home with a brother/sister with developmental disabilities.

RESULTS

Of 363 themes identified, 61.1% reflected negative manifestations of increased risk in well siblings; 1.7% indicated no risk; and 37.2% reflected positive outcomes, suggesting the continued need for potential interventions.

CONCLUSION

Contemporary family life in these families, as portrayed by parents' descriptions, reflects need in child health care for more intervention research on this vulnerable population.

Family decision making: benefits to persons with developmental disabilities and their family members

Family involvement in planning and choosing services has become a key intervention concept in developmental disability services. This study (N = 547) modeled patterns of family decision making and assessed benefits to persons with developmental disabilities (DDs) and their family members. A latent profile analysis identified 4 classes that were highly involved in decision making (n = 118), involved only in planning (n = 166), involved only in financial decisions (n = 75), and uninvolved (n = 188). Multiple regression analysis indicated that consumers with DD whose family members were highly involved received more services than consumers in other families. A multivariate analysis of covariance indicated that the family members in the highly involved and planning classes experienced more family member satisfaction than others. Findings have implications for practice.

Formative and Summative Evaluation of a Practice Doctorate Program

Practice doctorate programs are developing rapidly to meet the American Association of Colleges of Nursing recommendation that advanced practice nurses will be prepared with a Doctor of Nursing Practice by 2015. Evaluation of nursing doctoral programs has focused almost exclusively on research doctorate programs. The authors examine formative evaluations from students enrolled in a practice doctorate program and summative evaluations provided by students at the time of and 1 year following graduation. Suggestions for nurse educators and administrators are presented.

In-home toxic chemical exposures and children with intellectual and developmental disabilities

Despite the focus on preventing toxic chemical exposures during pregnancy, the perinatal period, and childhood, health professionals have given little attention to the risks and effects of toxic chemical exposures on children with intellectual and developmental disabilities (DD). Children with DD may be at higher risk due to behaviors that persist past a developmentally appropriate age, communication skills, motor skills, nutrition issues, and health problems related to DD. This article examines exposure of children to lead, mercury, and environmental tobacco smoke, three toxicants known to affect children's health and development. The authors identify sources of these toxicants, examine research documenting their effects on children, consider strategies to prevent and manage exposure, identify characteristics and behaviors placing children with DD at increased risk of exposure, and discuss implications for health providers.

A community-based intervention for siblings and parents of children with chronic illness or disability: the ISEE study

OBJECTIVE

Siblings of children with chronic illness or disability have been reported to have a 1.6 to 2.0 risk for behavioral and mental health problems. Our objective was to examine the effects of an intervention for siblings (age 7-15 years) of children with chronic illness or disability.

METHOD

A randomized, three-group repeated-measures design was used: full intervention (n=79), partial intervention (n=71), and a waiting list control group (n=102). Outcomes were sibling knowledge about illness, behavior problems, social support, self-esteem, attitude, and mood measured over four postintervention periods. Covariates were family cohesion, maternal mood, socioeconomic status, and well sibling age. The full intervention included structured teaching and psychosocial sessions at a 5-day residential summer camp. The partial intervention included camp only. Treatment effects were estimated by using generalized estimating equation panel analyses.

RESULTS

The full treatment group showed significant improvements on all six outcomes over most periods, the partial treatment group on three outcomes, and the control group on two outcomes. Improvements in outcomes ranged from 5% to 25% increases over baseline measures.

CONCLUSIONS

A dose-response relationship to intervention was found. Treatment gains were sustained over a period of 12 months.

Interrelationships among variables affecting well siblings and mothers in families of children with a chronic illness or disability

A structural equation model (SEM) examined interrelationships among psychosocial variables known to affect the health and development of well siblings and parents when a child with a chronic illness or disability is a member of the family. Using dyads of 252 well children and parents, socioeconomic status (SES) and family cohesion were associated with the parent-reported behavior of the well sibling. SES also influenced the mood of the mother that in turn influenced family cohesion. The well sibling's knowledge about the illness of the brother or sister, attitude toward the illness, mood, self-esteem, and feelings of social support were interrelated and related to the behavior of the well sibling. The SEM suggests that interventions may be directed at several points in these interactions including boosting knowledge levels of the well sibling, improving family cohesion, and assuring adequate "income" support to the family through income transfers or in-kind services.

Child rearing in the new independent states: a review of the literature

Child rearing in the New Independent States (NIS) is explored through a literature review examining child rearing practices in the former Union of Soviet Socialist Republics and the NIS. As exchanges between the NIS and other countries are underway, this information will help nurses understand issues faced by citizens of the NIS, families immigrating from the NIS, and health care professionals visiting the NIS. This review raises questions about NIS child rearing practices and may serve as a stimulus for further exploration of issues related to the health of children and families living in or emigrating from the NIS.

Guidelines for working with students having special health care needs

Students with special health care needs present challenges to persons involved with their education, but school staff are accepting the challenge to create safe, nurturing, and stimulating environments for these students. This article proposes guidelines for school staff working with students having special health care needs. The guidelines evolved from the authors' experiences and are child-related, family-related, and school-related. Discussion of each guideline includes illustrations of issues arising from them. Considerations for implementing the guidelines are presented and include discussion of school policies and procedures and state laws and regulations related to school staff working with students having special health care needs.

Facilitated transport of 6-mercaptopurine and 6-thioguanine and non-mediated permeation of 8-azaguanine in Novikoff rat hepatoma cells and relationship to intracellular phosphoribosylation

6-Mercaptopurine and 6-thioguanine strongly inhibited the zero-trans entry of hypoxanthine into Novikoff rat hepatoma cells which lacked hypoxanthine/guanine phosphoribosyltransferase, whereas 8-azaguanine had no significant effect. 6-Mercaptopurine was transported by the hypoxanthine carrier with about the same efficiency as its natural substrates (Michaelis-Menten constant = 372 +/- 23 microM; maximum velocity = 30 +/- 0.7 pmol/microl cell H2O per s). 8-Azaguanine entry into the cells, on the other hand, showed no sign of saturability and was not significantly affected by substrates of the hypoxanthine/guanine carrier. The rate of entry of 8-azaguanine at 10-100 microM amounted to only about 5% of that of hypoxanthine transport and was related to its lipid solubility in the same manner as observed for various substances whose permeation through the plasma membrane is believed to be non-mediated. Only the non-ionized form of 8-azaguanine (pKa = 6.6) permeated the cell membrane. Studies with wild type Novikoff cells showed that permeation into the cell was the main rate-determining step in the conversion of extracellular 8-azaguanine to intracellular aza-GTP and its incorporation into nucleic acids. In contrast, 6-mercaptopurine was rapidly transported into cells and phosphoribosylated; the main rate-determining step in its incorporation into nucleic acids was the further conversion of 6-mercaptopurine riboside 5'-monophosphate.

Hexose transport in Novikoff rat hepatoma cells. A simple carrier with directional symmetry, but variable relative mobilities of loaded and empty carrier

The kinetics of transport of the non-metabolizable hexose, 3-O-methyl-D-glucose, have been measured in Novikoff rat hepatoma cells by both zero-trans entry and equilibrium exchange procedures. Transport conformed to a simple carrier model which operates symmetrically with respect to direction, but with greater mobility of the loaded than of the empty carrier. Although a complete kinetic description of the transporter can, in theory, be obtained by application of integrated equations describing the time course of substrate equilibrium across the membrane beginning from the zero-trans situation, statistical analysis of hypothetical data indicated that directional asymmetry or differential mobilities of loaded and empty carrier cannot be discerned reliably from such data alone. The difference in mobility of loaded and empty carrier, apparent in a comparison of zero-trans entry and exchange data, ranged from 1.5--7-fold in different batches of cells. It is concluded that the magnitude of the difference is not an inherent property of the transporter, but is determined physiologically, and may be involved in regulation of hexose transport.

Deoxyglucose and 3-O-methylglucose transport in untreated and ATP-depleted Novikoff rat hepatoma cells. Analysis by a rapid kinetic technique, relationship to phosphorylation and effects of inhibitors

Detailed time courses of uptake of labeled 3-O-methyl-D-glucose and 2-deoxy-D-glycose by untreated and ATP-depleted Novikoff rat hepatoma cells were determined as function of concentration (0.2-10 mM) by a rapid mixing/sampling technique which allows uptake measurements in time intervals as short as 1.5 seconds. Intracellular accumulation of 3-O-methylglucose in untreated and ATP-depleted cells and of deoxyglucose in ATP-depleted cells to equilibrium followed pseudo-first order kinetics and initial velocities were computed from overall time courses of substrate accumulation. Initial velocity was a Michaelis-Menten function of exogenous substrate concentration. The estimated kinetic constants for zero-trans transport of 3-O-methylglucose were about the same for untreated and ATP-depleted cells (Kztm = 1.73 +/- 0.24 mM; Vztmax = 28.8 +/- 3.6 pmoles/microliter cell H2O. sec) and were similar to those for deoxyglucose transport in ATP-depleted cells (Kztm = 0.65 +/- 0.1 mM; Vztmax = 19.6 +/- 1.6 pmoles/microliter cell H2O. sec). Similar kinetic parameters were obtained for the transport of D-glucose and D-galactose in ATP-depleted cells. The transport of 3-O-methylglucose and deoxyglucose were inhibited by each other in a simple competitive manner with apparent Ki's similar to their transport Km's. In untreated cells, in which deoxyglucose was phosphorylated, intracellular steady-state levels of free deoxyglucose accumulated within 10 to 20 seconds of incubation regardless of its concentration in the medium. Thereafter, the rate of deoxyglucose incorporation into total cell material reflected the rate of phosphorylation rather than the transport rate. The rate of deoxyglucose transport exceeded the initial rate of its phosphorylation by 20-40 %. The intracellular steady-state-levels observed during the first 2 minutes of incubation decreased from about 40% of equilibrium level at 0.2 mM deoxyglucose to about 8% at 10 mM. Computer fits of a kinetic equation describing transport and phosphorylation as independent processes operating in tandem to these data are consistent with the observed kinetic constants for hexose transport and hexokinase activity with deoxyglucose as substrate. Upon longer incubation (2-10 minutes) the rate of deoxyglucose uptake by the phosphorylating cells decreased progressively, concomitant with a decrease in intracellular ATP and an increase in intracellular deoxyglucose to equilibrium levels. It is demonstrated that the rate of deoxyglucose uptake, measured at two or more minutes, seriously underestimates the hexose transport rate and yields misleading conclusions regarding the extent and type of inhibition by transport inhibitors, such as persantin or cytochalasin B. Persantin inhibited hexose transport in a simple non-competitive manner (Ki = 20 muM) indicating that the drug affects the function of the hexose carrier.

Mechanism of action of inosine dialdehyde (NSC 118994) in the inhibition of proliferation of tumor cells in culture

Inosine dialdehyde (INOX), the periodate oxidation product of inosine, inhibited the proliferation of various tumor cell lines in suspension culture in a concentration-dependent manner. A concentration of about 1 mM was required to completely inhibit the proliferation of Novikoff rat hepatoma and mouse L-cells, whereas about 0.1 mM completely inhibited the proliferation of L1210 and P388 mouse leukemia and Chinese hamster ovary cells. INOX inhibited in a similar time- and concentration-dependent manner the synthesis of protein, RNA, and DNA, as measured by the incorporation of labeled amino acid, uridine, and thymidine, into acid-insoluble material, without significantly affecting the incorporation of these precursors into the acid-soluble pool. Flow microfluorometric analyses showed that many of the INOX-treated cells became arrested in G2 + M. The results are consistent with the view that INOX affects multiple metabolic steps. The effects of INOX were quite different from those caused by typical inhibitors of ribonucleotide reductase, hydroxyurea, and 2,3-dihydro-1H-pyrazolo(2,3-a)imidazole, which very rapidly inhibited DNA synthesis and caused arrest of the cells in G1, with minimal effects on RNA and protein synthesis.